Separation of tar and ammonium chlorid contained in gases produced by distilling coal.



UNITED s ATEs PATENT OFFICE.

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tion of Tar and 1,052,853. No Drawing.

To all whom it may concern: Y

Be it knownathat I, Lotus '-SOLVAY, a subject of theKing of the Belgians, resid-v ing at Brussels, Belgium, have invented new and useful Improvements in Separa- Ammonium Chlorid Con- Produced by Distilling following is a specificatained in Gases Goal, of which the tion. y y This invention. relates to improved separation of tar and ammonium chlorid contained in gases produced by distilling coal in coke ovens and gasworksf By the use of apparatus'such as described in the specification of prior Letters Patent No. 963,401 in which the gases produced by distilling coal are washed infa bubbling column or gas scrubber with tar, the tar con-' tained in the gases can be easily removed and the saturationof the ammoiiia,.tl1at is to say the combination of the ammonia with acid to form a salt can then be easily 'ef fected by direct washing of the gases in sulfuric acid after the tar is removed. The apparatus described in the said prior specification enables different temperatures to be obtained in the diiferent superposed sections or compartments of the bubbling column or scrubber, and, by suitably regulating. the temperatures, a practically anhydrous tar can be withdrawn Idirectly from the treated gases, the commercial value of such tar being greater than that of tar which contains Water. Such a method of working has however a disadvantage in that the separation of ammonia already in combination in the gases as ammonium ehlorid and which condenses with the tar in a. quantity which is of certain coals,

variable, and, in the case often considerable, is requiring special manipulation giving imperfect results.

The object of the present invention is to obviate this disadvantage. According thereto the ammonium chlorid is separated in a solid state from the gas previous to the introduction of the latter into the apparatus for removing the tar.

- Since the apparatus directly receives the tar which is already condensed in the hydraulic main of the furnaces all separation or sublimation,hereinafter termed (:Ondensu; tion of the ammonium ehlorid therein should be avoided and this may be e ll'ccted by preventing the local causes of cooling. On the and only specification ot iettera Patent. Application filed man 16,1912. Serial no. ea4,ase.

a delicate operation i'leposited therein.

tamed Feb. 11,1913.

other hand notwithstanding the large gaseous volumes to be nium chlorid, it- "is necessary to'preve'nt any of the ammonium chlorid being carried along by the uses. Now it has been ascertained that if te gases issuing from the hydraulic main are cooled on their way to the tar removing apparatus to 'a temperature which may vary from 180 to 120 (one hundred and eighty to one hundred and twenty) degrees centigrade, according to the amount of chlo- 7 treated and the well known considerable vaportension of ammo rid contained in the gases, :1 small portion of the tar will be deposited and, owing probably to its vesicular state, carrywithfit the particles of ammonium chlorid which it retalus completely. Fromthis it wili'fbe' understood that it'is sufiicient-to avoid all'condensationof the "ammonium chlorid in the hydraulic main in order to 'be able to efiect the total condensation thereof intoa solid state in a cooling apparatus of anyfsuita'b'le kind placed between the hydraulic m'aina'nd the apparatus for removing, the tar. 'J'I'n order to facilitate the removal offthe condensed salt by washing or otherwise two coolers may be used so arranged that the salt may be removed from one whileths otheris working.

The general working of the process may therefore be as follows: The gases pass through the hydraulic main which is mainmined as hot to prevent any condensation of'the ammonium chlorid. A temperature of about as possible by a. suitable jacket 35 0 C. is sufiicient for this purpose. The gases then pass into a cooler whereltheirtcnmerature is lowered to from 180 to 120 (one hundred and eighty to one hundred and twenty) degrees centigrade' so that the ammonium chlorid' which they contain is" The gases are then led to the tar rcmoving'apparat us from whence they pass to the sulfuric acid saturato'r.

It will be seen that theim'proved recess permits of the direct recovery of t e ammonium chlorid in the solid state independently of the recovery of an anhydrous tar of a quality superior to that of ordinary tar."

Having now described my invention,what Iv claim as new and desire to secure by Let: ters Patent is:-

1. Process for the separation of tar and ammonium chlorid contained in the gases produced by distilling coal, consisting -monium chlorid to de -posit simultaneously with a small portion 0 the tar and the said gases are finally passed through a'suitable tar removing apparatus wherein condensadrous tar from the. gases produced by distion of water vapor, 1s avoided by maintain in therein-suits 1e temperatures.-

'- Pro ess for the separatlonof'tar and ammonium chlorid contained in the gases reduced by distilling coal consisting in- .maintaining a. 'suflicient temperature in the hydraulle main of the furnace to prevent condensation therein of ammonium chlorid,

CMISIDE 2a the esissuing said mam-t0 pass roug a sultable cooling apparatus where n they are cooled to a temperature of 180 to 120 degrees centigr'ade and after ward through a tar removing apparatus- 2-5- wherein the temperature is maintained suchas to avoid condensation of .water vapor therem.

I 3. Process for the separation of at and about 350 of water' vapor therein.

noeaieoe ammonium chlorid contained in the gases produced by distilling coal consistin in first separating the ammonium chlori together with a small portion of the tar by cooling the gases issuing from the hydraulic -main to a temperature of 180-120 G. and

afterward separating the'remaining portion of the tar in a practically. anhydrous condition.

4., In the separation ofpractically anhytilli'ng coal, the process for obtaining nearly all the tar free fr0m ammonium chlorid consisting in maintaining a, temperature of C. in the hydraulic main, lowering to 180-120 C. the temperature of the gases between said" hydraulic main and the tarremover and maintaining a suitable temperature in the latter to 4 In testimony whereof I have aflixed my signature in" presence of two subscribing witnesses.

' LOUIS SOLVAY.

F. Josial'n Lanna.

avoid condensation 

